<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <ul>
        <li style="list-style-type:none;"><h>高度：</h><input id="width" type="text" /></li>
        <li style="list-style-type:none;"></li><h>宽度：</h><input id="height" type="text" /></li>
        <!-- <input id="calculate" type="button" placeholder="计算"/> -->
        <li style="list-style-type:none;"></li><button id="calculate">计算</button></li>
        <li style="list-style-type:none;"></li><h>周长：</h><input id="perimeter" type="text" /></li>
        <li style="list-style-type:none;"></li><h>面积：</h><input id="area" type="text" /></li>
    <ul>
</body>
</html>